A machine for compressing or expanding gas comprises a piston operating downwards in a compression stroke with respect to an inclined or vertical cylinder and upwards with respect to the cylinder in an expansion stroke. The piston has a heat absorbing and releasing structure attached to its bottom face. There is a gap between the piston and the base of the cylinder when the gas volume in the cylinder is at its minimum. The gap contains a hydraulic fluid which absorbs heat from the heat absorbing and releasing structure. A heat transfer surface containing fluid circulating to and from an external source maintains the hydraulic fluid at constant temperature. In one arrangement the heat absorbing and releasing structure comprises thin sheets of aluminium attached orthogonally to the bottom face of the piston.

A machine for compressing or expanding gas comprises a piston operating downwards in a compression stroke with respect to an inclined or vertical cylinder and upwards with respect to the cylinder in an expansion stroke. The piston has a heat absorbing and releasing structure attached to its bottom face. There is a gap between the piston and the base of the cylinder when the gas volume in the cylinder is at its minimum. The gap contains a hydraulic fluid which absorbs heat from the heat absorbing and releasing structure. A heat transfer surface containing fluid circulating to and from an external source maintains the hydraulic fluid at constant temperature. In one arrangement the heat absorbing and releasing structure comprises thin sheets of aluminium attached orthogonally to the bottom face of the piston.

Autonomous fluid compressor for supplying compressed fluid to a cable laying device, the fluid compressor comprising a fluid compressing unit arranged to compress fluid and comprising an exhaust valve, an electric motor, for driving the fluid compressing unit, a rechargeable power unit, to supply electric power to the electric motor, a fluid supply port connected to the exhaust valve, characterized in that the fluid compressor including an input unit, for receiving a fluid demand signal indicating a fluid demand from the cable laying device, and a control unit, arranged to control the motor based on the fluid demand signal.

Autonomous fluid compressor for supplying compressed fluid to a cable laying device, the fluid compressor comprising a fluid compressing unit arranged to compress fluid and comprising an exhaust valve, an electric motor, for driving the fluid compressing unit, a rechargeable power unit, to supply electric power to the electric motor, a fluid supply port connected to the exhaust valve, characterized in that the fluid compressor including an input unit, for receiving a fluid demand signal indicating a fluid demand from the cable laying device, and a control unit, arranged to control the motor based on the fluid demand signal.

A reduced-pressure device includes a housing having recesses on sidewalls thereof, an air pressure storage unit and a compression unit. The air pressure storage unit is installed in the housing and comprises a pressure storage container, a piston assembly and a piston spring, and the compression unit is mounted on the piston assembly. The compression unit further includes a pressing element and a turntable. The pressing element is accommodatable in the recesses of the housing, and rotatable by the turntable in relative to the air pressure storage unit and the housing, and when the pressing element is pulled out of the recesses and rotated to a predetermined position to compress the piston assembly to produce a negative pressure in the pressure storage container, the pressing element can be rotated back to the original position to be accommodated in the recesses again after using.

A reduced-pressure device includes a housing having recesses on sidewalls thereof, an air pressure storage unit and a compression unit. The air pressure storage unit is installed in the housing and comprises a pressure storage container, a piston assembly and a piston spring, and the compression unit is mounted on the piston assembly. The compression unit further includes a pressing element and a turntable. The pressing element is accommodatable in the recesses of the housing, and rotatable by the turntable in relative to the air pressure storage unit and the housing, and when the pressing element is pulled out of the recesses and rotated to a predetermined position to compress the piston assembly to produce a negative pressure in the pressure storage container, the pressing element can be rotated back to the original position to be accommodated in the recesses again after using.

One or more techniques and/or systems are disclosed for a pump technology that provides for more effective and efficient transfer of liquids, such as glycol products, in a glycol dehydration system. Such a technology can comprise a type of external gear pump that can effectively handle harsh conditions associated with glycol dehydration system at high pressures, while providing for longer pump life, effective operations at higher temperatures, and operations that account for thermal shock; with improved sealing capability, in a cost-effective system. An example pump may comprise hardened internal components, improved clearances, a jacket to mitigate thermal shock, and/or a thermal shock plate to mitigate thermal shock.

A press puffing device includes a piston support, a nozzle holder, and a sealing fixer. In the press puffing device, a power supply start button is pressed to produce an aroma gas, and the aroma gas is contained in the cylindrical inner cavity. By pressing the piston support, the contained smoke is compressed and flows to the air outlet through the lateral gas channel to spurt out.

A press puffing device includes a piston support, a nozzle holder, and a sealing fixer. In the press puffing device, a power supply start button is pressed to produce an aroma gas, and the aroma gas is contained in the cylindrical inner cavity. By pressing the piston support, the contained smoke is compressed and flows to the air outlet through the lateral gas channel to spurt out.

An instrument air system and method is disclosed herein. The instrument air system includes a shaft-driven air compressor configured to generate instrument air by compressing atmospheric air, a power take off configured to derive drive torque from a driven rotary shaft of the process, wherein the power take off may include a concentrically-mounted clamping collar adapted to frictionally engage the driven rotary shaft, a torque-transfer assembly configured to transfer the drive torque derived by the power take off to the shaft-driven air compressor, wherein the torque-transfer assembly comprises a set of interoperating gears including a ring gear operably coupled to the clamping collar, and an instrument-air pathway configured to supply the instrument air generated by the shaft-driven air compressor to the pneumatic process-control subsystem. The instrument air system and method is useful for reducing hydrocarbon emissions of a process using a pneumatic process-control subsystem.